In recent years and continuing, studies and research have been made on molecular communication systems using nano-scale chemical substances (molecules) as information carriers. With a molecular communication system, communication is established based on biochemical reactions caused upon reception of the information encoded molecules. See, for example, S. Hiyama, et al., “Molecular Communication,” Proceedings on NSTI Nanotechnology Conference and Trade Show 2005, vol. 3, pp. 391-394, May, 2005, as well as S. Hiyama, et al., IEICE magazine, Vol. 89, No. 2, pp. 162-166, February, 2006.
Unlike existing communication technologies that use electromagnetic waves (electric signals or optical signals) as information carriers, molecular communication uses biochemical signals which produce slow speed communication with low energy consumption. Molecular communication has high potential for application to communications between nano-scale devices that cannot use electromagnetic waves for capability reasons or environmental reasons and operational control of nanomachines that are not composed of electronic components and cannot be driven by electronic signals.
A molecular communication system generally includes a molecular transmitter, a molecular receiver, and a molecule propagation environment connecting the molecular transmitter and the molecular receiver. The information-coded molecules (which may be referred to simply as “information molecules”) transmitted from the molecular transmitter propagate through the propagation environment (or transmission channel) to the molecular receiver. The molecular receiver captures the propagated information molecules, decodes the information, and expresses a biochemical reaction to the information molecules. In order to protect the information molecules from degrading enzymes existing in the propagation environment or from the influence of temperature, acid or base (represented as a pH value), or light, it is also proposed to encapsulate the information molecules in a molecular capsule. See, for example, Y. Moritani, et al., “Molecular Communication among Nanomachines Using Vesicles,” Proceedings on NSTI Nanotechnology Conference and Trade Show 2006, Vol. 2, pp. 705-708, May 2006.
One of the candidates for a molecular transmitter and/or receiver used in the molecular communication system is a living cell because a living cell has the basic functions of a molecular transmitter/receiver. However, the structures and behaviors of living cells are complicated, and it is very difficult to artificially design and control the functionality of living cells.